Reference values have been established for serum biochemical parameters in sows from high producing pig herds. In total, 132 clinically healthy sows from eight breeding herds were serially sampled three weeks and one week before farrowing, and at one week and three weeks after farrowing. Fourteen serum biochemical parameters, focusing mainly on energy and protein metabolism, hepatobiliary and kidney function and inflammation, were investigated. The reproductive state significantly influenced the investigated parameters, other than for urea and non-esterified fatty acids. First parity sows showed higher concentrations of γ-glutamyltransferase, phosphorus and haptoglobin, and higher albumin/globulin and haptoglobin/albumin ratios compared to sows with ⩾2 parities. The concentrations of creatinine, globulin and total protein however were lower in first parity sows. Between-herd variations were especially high (>50%) for γ-glutamyltransferase, alkaline phosphatase and non-esterified fatty acids. Serum biochemical parameters constitute an important diagnostic tool to assess the health status of sows, but to interpret the outcome properly, it is important to consider reproductive state and parity.

Serum biochemical reference values for gestating and lactating sows

Introduction The present article reviews the histochemical techniques that have been used to detect the Na /K , Ca2 , and H /K ATPases in plasma membranes. ATPases are a group of intrinsic enzymes which utilize ATP as their substrate or energy source and are activated by one or more cations, including Na , K , Ca2 , H , and perhaps anions such as Cl. In many cases ATPases are the molecular machinery that drives transport of the relevant ions. The mechanisms of vectorial ion movement are not well understood, but the principal underlying biochemical reactions are established (4,24,85).

Histochemistry of ATPases.

To examine the vasculature of the areola-gland subunit of advanced pig placenta, tissues from ten animals between 43 and 112 days of gestation were prepared for histology and for scanning electron microscopy of vascular corrosion casts from both maternal and fetal sides. Regular areolae, tributary to one gland only, are round with a wide-meshed and smooth subepithelial capillary network on the maternal side, which is similar to the pre-implantative stage and bordered by an abrupt rim towards the interareolar maternal capillary network. On the fetal side, the capillary network follows papillae which protrude into the areolar cavity or converge to form a ring towards the areolar periphery. Irregular areolae, in contrast, have indistinct boundaries and are characterized by two or more gland openings. The maternal capillary network has moderate density and follows the corrugations, whereas the fetal capillary network is basically two-dimensional with some blunt sinusoidal protrusions. Vessel architecture of both areolar types implies facilitated external inflow of blood into the areola on arteriolar as well as on capillary levels, whereas the outflow from the areolar capillaries comprises venules converging into one or two areolar stem veins, and therefore conducts venous blood in a manner different from that of the interareolar region. It is suggested that this arrangement could favour vascular control mechanisms in uterus, placenta and fetus. On the basis of these observations and the discussion, it is suggested that these areolaspecific vessel systems are important for sustaining the characteristic substance transfers in the areola, the secretion, metabolism and absorption, which according to the literature are not the same in the regular as in the irregular areolar type of the porcine areola-gland subunit of the placenta.

Microvasculature of regular and irregular areolae of the areola-gland subunit of the porcine placenta: structural and functional aspects

Na+,K+-ATPase histochemistry, using direct (Pb) and indirect (Mg/Sr-Co) p-nitrophenyl phosphatase methods, was assessed by scanning integrative microdensitometry of three classes of tubules in mouse and guinea pig kidneys. The methods yielded similar and appropriate patterns of activity distribution and inhibitor response. The indirect method gave preferable results, in that non-enzymic background was lower and rate of reaction product accumulation was considerably higher.

J.A. Frith

Papers

Histochemical localization of phosphotases in the pig placenta: I. Non-specific phosphatases and their relation to uteroferrin